de Souza C P, Araújo N, Jannotti-Passos L K, Guimarães C T
Centro de Pesquisas René Rachou, FIOCRUZ, Belo Horizonte, MG, Brasil.
Rev Inst Med Trop Sao Paulo. 1994 Nov-Dec;36(6):485-9. doi: 10.1590/s0036-46651994000600002.
The snail density, levels of infection and the monthly production of Schistosoma mansoni cercariae by Biomphalaria glabrata were determined in a focus of Barreiro de Baixo (Belo Horizonte, MG, Brazil). During a period of 38 months (1984 to 1987) 5,366 snails were collected of which 324 (6.03%) were infected with S. mansoni. The total number of cercariae shed was 5,667,312. Each snail shed an average of 17,422 cercariae during the time that it was under study in the laboratory. The greatest longevity of infected snails was 218 days. Natural cure was observed in 42 (12.9%) of the infected specimens about 130 days after collection. The average snail density in the focus during the period of study was 16.3 snails per scoop. The shedding of cercariae by snails collected from the field was compared with laboratory bred specimens infected in mass with the LE strain of S. mansoni from Belo Horizonte. The laboratory infected snails shed an average of 6,061 cercariae each, a value 2.8 times less than the field specimens due to a shorter life span. The prevalence of schistosomiasis in the focus was 14.3%.
在巴西米纳斯吉拉斯州贝洛奥里藏特市的下巴雷罗地区的一个疫点，测定了光滑双脐螺的蜗牛密度、感染水平以及曼氏血吸虫尾蚴的月产量。在1984年至1987年的38个月期间，共收集了5366只蜗牛，其中324只（6.03%）感染了曼氏血吸虫。尾蚴的总排出量为5667312条。在实验室研究期间，每只蜗牛平均排出17422条尾蚴。感染蜗牛的最长寿命为218天。在采集后约130天，观察到42只（12.9%）感染标本出现自然治愈。在研究期间，该疫点的蜗牛平均密度为每勺16.3只。将从野外采集的蜗牛排出尾蚴的情况与在实验室用来自贝洛奥里藏特的曼氏血吸虫LE株大量感染的养殖标本进行了比较。实验室感染的蜗牛平均每只排出6061条尾蚴，由于寿命较短，该值比野外标本少2.8倍。该疫点的血吸虫病患病率为14.3%。
